Astronauts living in space are forced to survive on pre-packaged, frozen meals delivered to them from Earth. But as space agencies start to visualize long-duration missions to planets millions of miles away, then a resource of food that keeps on giving is more ideal.
Luckily, scientists have recently proven that you don’t need large plots of land in order to grow your own food. In fact, sometimes all you need is a small chamber with LED lighting tucked away on a spacecraft floating 254 miles above Earth.
A study published Friday in the journal Frontiers in Plant Science examined the first crop of red romaine lettuce grown onboard the International Space Station (ISS), giving space lettuce the green light as safe to eat and just as nutritious as Earth lettuce.
"We were very excited to see the plants growing via photos and videos from the astronauts. They looked very similar to their Earth-grown counterparts,” Christina Khodadad, a researcher at the Kennedy Space Center, and lead author of the new study, tells Inverse. "These results indicated that plants will grow similarly to their ground counterparts in spite of the stresses they might experience in microgravity."
Cream of the crop
The lettuce started growing on the ISS in May, 2014 as part of an experiment called Veg-01 where pillows of seeds were watered and cared for by crew members of Expedition 39.
Red romaine lettuce of the 'Outredgeous' cultivar was grown in the Vegetable Production Systems, nicknamed Veggie, that features a flat panel light bank that includes red, blue and green LEDs. The blue and the red wavelengths are used for plant growth, while the green is so that the crew members can observe the plants.
The crops were left to grow for 33 days before being harvested and sent down to Earth to be analysed and ensure they were safe to eat. In August, 2015, NASA’s Kennedy Space Center finally gave the okay for the astronauts onboard to enjoy the greens of their labor.
Expedition 44 crew members got to sample half of the harvest, while sending the other half to Earth for chemical and biological analysis.
Meanwhile on Earth, scientists were also growing their own batch of lettuce within the same veggie chambers where the same temperature, humidity and carbon dioxide levels were replicated at laboratories at the Kennedy Space Center.
The researchers examined both samples of the crop, comparing the level of nutrients.
Space lettuce passed the test, and was free of disease causing microbes and just as nutritious as its Earth counterpart despite being grown in a microgravity environment and with more intense levels of radiation than on Earth, according to the study.
The lettuce grown onboard the ISS had a similar composition, and in some samples tended to be richer in elements such as potassium, sodium, phosphorus, sulphur, zinc, and phenolics, which have antiviral, anticancer, and anti-inflammatory properties. The two crops also had similar levels of antioxidants.
The researchers also examined the microbial communities growing on the lettuce, and found that both space and Earth grown lettuce had the same level of diversity of these microbes. This finding was surprising since the team of researchers had expected unique microbial communities to develop on the space lettuce as a result of the environmental conditions on the ISS.
However, none of the microbes detected were ones that carried any harmful bacteria that could affect human health such as coliform E. coli, or Salmonella.
The successful cultivation of fresh produce on the ISS is a game changer for future space travel.
Not only is having fresh greens more nutritious for the astronauts, providing them with more vitamins and nutrients, but it would also mean a sustainable resource for food onboard spacecraft.
“The International Space Station is serving as a test bed for future long-duration missions, and these types of crop growth tests are helping to expand the suite of candidates that can be effectively grown in microgravity,” Gioia Massa, project scientist at Kennedy Space Center, and co-author of the new study, said in a statement.
NASA is hoping to apply what they learn on the ISS in urban plant factories and other agriculture settings where light is provided by electrical light and water conservation is practiced, according to the space agency.
"What we are learning from space agriculture can translate well into controlled environment agriculture on Earth, and aspects like sensing stress or environmental factors or disease before they become growth limiting to crops," Khodadad says.
Future testing will grow other ingredients for a hearty salad, such as small fruits like peppers and tomatoes, in order to provide more produce options for astronauts.
The researchers also suggested that astronauts onboard the ISS enjoyed the process of growing their own plants, and tending to them during their time floating in space.